The Trinitarian Theology of Saint Thomas Aquinas - El Camino ...

12 Revelation of the Trinity
recognize a diversity of substance because ‘diVerent actions indicate diVerent
natures’.23 St Thomas explains:
when we want to know if a certain thing is true, we can determine it from two things:
its nature and its power. For true gold is that which has the species of true gold; and we
determine this if it acts like true gold. Therefore, if we maintain that the Son has the
true nature of God, because the Son exercises the true activities of divinity, it is clear
that the Son is authentically God. Now the Son does perform true works of divinity,
for we read, ‘Whatever he [the Father] does, that the Son does likewise (5.19); and again
he said, ‘For as the Father has life in himself,’ which is not a participated life, ‘so he has
granted the Son also to have life in himself ’ (Jn 5.26); ‘That we may be in his true Son,
Jesus Christ. This is the true God and eternal life’ (1 Jn 5.20).24
These actions are not restricted to the miracles which Christ once performed,
but extend to the whole of his activity; he continues to act on believers’ behalf
today, as Scripture attests. For this reason, the experience of salvation which
we receive from Christ leads us to recognize his divinity and his eternal unity
with the Father:
a person participating in the word of God becomes god by participation. But a thing
does not becomes this or that by participation unless it participates in what is this or
that by its essence . . . Therefore, one does not become god by participation unless he
participates in what is God by essence. Therefore, the Word of God, that is the Son, by
participation in whom we become gods, is God by essence.25
One recognizes here the soteriological argument that Athanasius liked, as did
many other Fathers of the Church.26 Thomas takes it over not only from
St Hilary, but also from St John Chrysostom and palpably from St Augustine
(as the Catena aurea on the passages which we have indicated here shows): if
Christ is not God, he could not save, for he could not renew the faithful in the
grace of the new creation, which is adoptive Sonship (meaning divinization).
The reality of salvation rests on the divinity of Christ who, because he is God,
enables us to participate in what he really is.
Alongside Christ’s own words and actions, Thomas examines the titles and
the names given to Christ by others (such as Son of God, Son, the Son, Word):
they express the divine intimacy of the Son with His Father, the divine relationship
which the Son has with the Father.27 St Thomas also considers the New
23 In Ioan. 14.16 (no. 1912). Taken to its logical conclusion, this would mean that, if the works
of the divine persons are different, the persons would not be of the same nature. But, according to
Thomas, the action of persons is identical: only the mode of this common action is distinct (see
below, in Chapter 14, ‘The Persons’ Distinct Modes of Action and their Unity in Action’).
24 In Ioan. 17.3 (no. 2187).
25 In Ioan. 10.35 (no. 1460). On this theme, see L.-B. Geiger, La participation dans la
philosophie de St Thomas d’Aquin, Paris, 1953, pp. 238–258.
26 Cf. for example Athanasius, De synodis 51 (PG 26.784). 27 Cf. SCG IV, chs. 2–3.